Corkscrew



FIG. 1 is a top, front, right side perspective view of a corkscrew showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof; and

FIG. 5 is a perspective view thereof in an alternate position. 

The ornamental design for a corkscrew, as shown. 